In the principal aspect the present invention relates to a mechanism for interlocking a series of vertical drawers in a filing cabinet or the like. More particularly, the invention relates to the construction of the component parts associated with a locking and anti-tip linkage mechanism in a cabinet of the type having drawers, slidable panels, and the like arrayed vertically. In addition, the invention relates to such mechanisms having a cable or linkage bar actuated locking mechanism.
Vertical filing cabinets may have two or more drawers and/or pivotal front panels or sliding panels mounted vertically one above the other. When one of the drawers or panels is open to its fullest extent for access to the contents of the cabinet, the center of gravity of the cabinet may be offset. A problem that can result from such an offset is a tendency of the filing cabinet to tip thereby possibly causing an injury or damage. Thus cabinet manufacturers have installed various devices, known as anti-tip interlock mechanisms, for multiple drawer and multiple panel cabinets to prevent the opening of more than a single drawer and thus to prevent unbalance of the cabinet and tilting thereof. Such anti-tip interlock mechanisms, in general, employ a linkage arrangement associated with the telescoping slides for the drawers, etc. whereby the opening of a single drawer or panel will activate the anti-tip interlocking mechanism causing it to preclude the opening of additional drawers or panels. Consequently, when a single drawer is opened, the remainder of the drawers or panels are locked or retained in the closed position and cannot be opened until the open drawer is returned to its closed position. A typical mechanism of this type is depicted in U.S. Pat. No. 5,352,030 entitled “Anti-Tip Device” and issued to Wolfgang Derle and Ronald G. Schenk on Oct. 4, 1994, which is incorporated herewith by reference. Another patent which discloses an anti-tip interlocking device is U.S. Pat. No. 6,238,024 B1 in the name of Kenneth Sawatzky entitled “Linkage Member for an Anti-Tip/Interlock Device” issued May 29, 2001 also incorporated herewith by reference.
Such prior art mechanisms are highly effective for their intended purpose, to maintain the unopened drawers or panels in a closed position while at the same time another single drawer or panel, etc. is in the open position. Various challenges with respect to such systems have remained, however, including improvement of the procedure for installation, service and/or repair of such systems. That is, often such systems will require parts especially engineered for a particular model of cabinet. Further, such systems typically do not easily accommodate changes in construction or changes in tolerance associated with the manufacture of filing cabinets. As a result, often repair or replacement or original installation of component parts of an anti-tip mechanism and linkage system may require re-engineering the entire system to accommodate a new cabinet design. Thus there has developed a need for an improved mechanism or system to permit interlocking control of multiple drawers and/or panels in a vertical cabinet array. There has also developed a need whereby such a system can be locked and unlocked easily and whereby the locking and unlocking mechanisms can be easily incorporated or installed with such systems. Further, there has developed a need for incorporating such systems in cabinet arrays which use drawers as well as pivotal and slidable panels.